Clear vertical grain wood boards are highly desired among wood products consumers; unfortunately however, vertical grain boards can be made only from relatively large logs. For instance, a 1.times.12 vertical grain clear board requires a log which is approximately at least 30 inches in diameter. The dwindling supply of old growth large logs has resulted in a significant decrease in availability of vertical grain boards. Small logs, in fact, yield substantially no vertical grain boards at all, but rather only what is referred to as flat grain boards.
"vertical grain" (VG) refers to those boards which are cut from the log in such a manner that the wide portion or face of the board, as opposed to its thickness portion, extends substantially perpendicularly to the direction of the annual growth rings or grain of the log, so that the rings form an angle of 45.degree. or more with the surface of the board, while "flat grain" (FG) refers to those boards in which the wide portion of the board, as opposed to its thickness portion, extends substantially parallel with the annual growth rings or grain of the log, so that all or some of the rings form an angle of less than 45.degree. with the surface of the board.
Vertical grain boards are more desirable for certain applications than flat grain boards because of several factors, including general appearance, a harder and smoother surface, and less tendency to warp. Vertical grain boards, especially clear boards, are particularly desirable for items such as doors, window and door frames, furniture, shelving, paneling and siding. The demand for such boards, even at high cost, continues to be large. Due to the increasing scarcity of large logs, which naturally results in an increasing scarcity of vertical grain boards, continuing increases in the price of such boards is expected, particularly as the cost of harvesting large logs in more remote locations increases.
As one solution to this problem, separate individual boards have in the past been edge glued together to form boards or panels of desired width. In some cases, there have been attempts to match the grain of the individual boards in order to provide a more natural appearance. However, even in those cases, it is quite noticeable that the resulting board has been produced by edge gluing two or more individual boards, i.e. the glue lines are quite distinct and the differences in the grain of the individual boards is quite distinct.
This process has been used with both vertical grain and flat grain boards. Although the glued-up or remanufactured board is as strong and as stable as a single board, and in many cases in more stable since certain types of stresses within individual boards may be compensated for by a particular arrangement of individual boards, there remains the high demand for boards having the appearance of a single board, particularly clear, vertical grain single boards. Current edge glued boards do not appear to satisfy that demand.
Another technique for producing wide vertical grain boards is to first face glue a plurality of separate, individual flat grain boards together, i.e. glue the wide dimension of individual flat grain boards together. The resulting combination is then rip sawn perpendicularly to the wide dimension (face) of the boards at successive intervals to form vertical grain boards. However, the glue lines of such vertical grain boards are clearly visible, and the composite nature of the boards is readily apparent. Further, the density of such boards will typically vary through the board.